Audience in the hall saw a 'different debate' last Sunday

Two different debates took place the other night between Ronald Reagan and Walter Mondale. One was on TV. The other was in Kansas City's Music Hall. Seventy million Americans saw the television version. About 2,000 of us saw the ''live'' one. Some of the differences were startling.

On TV, Mr. Reagan looked sharper, more expressive, more in charge. Mr. Mondale came across as more weary, wooden, and dull. Those of us in the live audience saw a Mondale who was more animated, who smiled more often, who looked more rested. The Reagan we saw consulted his notes more often and seemed to pause more frequently in his answers. Thanks to video recording, those of us in the studio audience later were able to see what most Americans saw.

Reporters who covered the debate ''live'' were assigned seats in the second balcony - a position where, unfortunately, we missed a lot of the important action. Sometimes we had trouble hearing what was going on. The panel of four journalists asking the questions had their backs to us. We also couldn't see the faces of the two candidates very well. They were simply too far away.

At the same time, we could see some things that the TV audience could not. We could watch Reagan's and Mondale's reactions to each other's answers. We could see more of their ''body language'' as they moved their hands and arms about to emphasize various points. The TV audience generally saw only a ''talking head.''

The most revealing difference of all was the faces of the two men. Reagan's face, as seen on TV, is expressive. The President doesn't just speak with words. He speaks with a frown, a smile, or an expression of ''aw, shucks.'' In the press balcony, what seemed like a pause was actually a moment in which Reagan was saying, with a facial expression or a head movement, ''Who, me?'' or ''How could you say that?'' His eyes are lively, his cheeks are pink, and all this comes through in living color on television.

Mondale's face, as seen on TV, is unexpressive. The mouth moves, the eyes blink, but the face shows very little other action except on a few occasions when he turns toward the President to make an accusation.

None of that was apparent to those of us in the press balcony. We were hanging on the words, and, as a result, we missed some of the most important elements of the debate.

The sharp differences between a live appearance and one on television is a political fact of life in modern America. The first major politician to suffer from this difference was Richard M. Nixon in 1960 when he debated John F. Kennedy. Mr. Nixon later said:

''More important than what you say is how you look on television.''

David Chagall, publisher of a political newsletter, Inside Campaigning, is among those who have made careful studies of the art of politicking on television. Mr. Chagall's first reaction upon watching Sunday night's debate was that ''Reagan's people must have won the battle over lighting.''

The lights, set up by technicians from CBS News, were at angles that emphasized the bags under Mondale's eyes, while at the same time they masked Reagan's neck wrinkles, Chagall says. As a result, Mondale looked far more weary than in the first debate.

''It made the two men look about the same age,'' says Chagall.

A number of strategy decisions had obviously been made since the first debate to help Reagan look more forceful, Chagall notes. This was apparent at the very outset, when Reagan strode three-quarters of the way across the stage to meet Mondale. The gesture helped refute the idea that Reagan was a President who wasn't ''in charge.''

In the first debate, Mondale used a debating ''trick'' that was very successful. He would turn to Reagan and speak in an accusing way directly at him. Reagan stared back blankly, and seemed thrown off his stride.

This time, says Chagall, Reagan avoided Mondale's stare by looking down. This helped Reagan focus on what Mondale was saying and helped Reagan concentrate on how he would respond. Looking down also helps a person avoid ''blank outs'' or moments of confusion of the kind that Reagan seemed to have in the first debate, the expert say.

Even clothing can be an important element in TV debating. Clothing sends a message to voters, and Chagall gave Reagan's choice of clothing better marks.

Mondale wore a dark blue suit, white shirt, and reddish tie with very small polka dots. The tie was a slight improvement over the first debate (Mondale wore a solid tie that time.) But Mondale still looked lawyerly, which isn't quite right for a Democratic candidate going for blue-collar votes.

Reagan, on the other hand, was just right. His gray suit looked slightly tweedy (scholarly), and his boldly striped tie and prominent handkerchief in his breastpocket gave him a jaunty, lively appearance - perfect for a candidate opposed to ''Washington bureaucracy.''

Reagan lost points primarily in two areas, Chagall suggests. His beginning was weak because of apparent nervousness. Later, he looked sheepish, rather than firm, when Mondale attacked him.

Mondale, on the other hand, did several things that good coaching could have avoided, Chagall says.

He licked his lips often, which made him look nervous and dry-mouthed. His grin ''really hurts'' because it makes him look not serious.

Other minuses for Mondale: He often speaks in a three-word rhythm, giving him a ''scolding schoolteacher image.'' His answers often seem too packaged and repetitious, and therefore boring. He twice mispronounced the name of US Rep. Romano L. Mazzoli (D) of Kentucky, co-sponsor of the Simpson-Mazzoli bill. Mondale said it ''Mazola,'' like the margarine.

''That's an unfortunate mistake when you are appealing for Italian-American votes,'' says Chagall.

Chagall, who watched the debate on TV like most Americans, thought Mondale was at his best talking about human rights and leadership. He thought his closing statement was good, and Mondale wisely rebuffed efforts to get him involved in the Reagan ''age'' issue.

Meanwhile, there remains the question: Is it better to watch these great debates on TV, or in person?

The best strategy is obviously both - if you are able to get one of the very scarce tickets for these events, and if you have access to a video recorder.

But if you have only one choice, TV is the ticket. That picture tube in your home assures you of the best seat in the house.